Hybrid Hierarchical Network Design Scheme with Wavelength Conversion

This paper proposes a hybrid hierarchical network design scheme with wavelength conversion (H2NDS) to design a low-delay network by integrating a conventional IP network and an optical network with wavelength conversion devices. In H2NDS, the network is divided into multiple domains, and wavelength converter devices and router devices are located at the relay node, an interconnection point between these domains. H2NDS is formulated as an integer linear programming problem to the sum of the delay of all end-to-end paths (delay) with constraint of the number of wavelengths in the optical network. Each end-to-end path selects the optimal relay node and selects either the router or wavelength converter devices to minimize the delay. The evaluation results showed that H2NDS significantly improved the delay performance compared to the benchmark model in which all end nodes belong to the nearest relay node, achieving a maximum reduction of 77.9 %.